A band ligation is generally understood to be the application of an elastically expanded ring band to the anatomical region of a living organism to be ligated by the ring band in its relaxed state.
A ligator system is generally comprised of a medical device referred to as a ligator, with which the ring bands serving for ligation are pulled over the anatomical region to be ligated, and the associated ring bands.
For this purpose, the ligator typically has a holding tube on whose outer circumference the ring band is placed. In the process, the ring band is stretched, so that the inner diameter of the ring band is enlarged considerably. The holding tube is put over the anatomical region to be treated, and the tissue to be ligated is brought into the holding tube, for example by being sucked in by the latter. Then, the ring band is pushed towards the distal end of the holding tube to such an extent that it comes off the holding tube; graphically speaking, this is referred to as “firing” the ring band, even though the process is of a purely mechanical nature. Once the ring band has come off the holding tube, it abruptly contracts elastically and thus ligates the anatomical region thus treated.
US 2006/0259 A1 discloses an endoscopic device with intermediate members which are radially deformed by means of pulling means so that the deformed intermediate member is no longer an obstacle to the next band being stripped off.
US 2011/0106116 A1 discloses a device for sealing openings in tissues. In the process, the band for sealing tissue is discharged in a controlled manner and placed by means of an actuating lever. These bands have not intermediate members; furrows that are integrally connected to the holding tube are placed on the latter.
It is desirable to be able to place several ring bands one behind the other onto the holding tube, in order to be able to “fire” them successively in a controlled manner at different sites to be treated and thus be able to produce a ligature at different sites, without having to place another ring band onto the holding tube of the ligator again in between. In practice, however, there is the problem, on and off, that two ring bands are inadvertently peeled off the holding sleeve at the same time if an attempt is made to place the ring bands on the tube one behind the other, which results in one and the same region to be treated being ligated by two ring bands. This is not only uneconomical and counterproductive with regard to the desired rapid working progress, but also involves the risk of medical complications for various reasons.
It is therefore the object of the present invention to provide a ligator system which offers enhanced security against inadvertently firing off two ring bands at the same time.